Shock absorber



A. R. ARNOT.

SHOCK ABSORBER.

- APPLICATION FILED NOV. 7. 1919.

1,41,098. te d ne 6, 1922.

W Hilly:

one form of which is illustrated as STA-S time SHOCK ABSORBER.

aiaoes,

Application filed November 7, 1919.

ers, of which the following is a specification.

This invention relates to vehicles and more particularly to springsupports for the bodies thereof, and has for its object to provide aspring device having the duel function of a recoil action and anover-load reaction, and a further object is to provide a device of thiskind that can be readily applied to spring arms in vehicles alreadyconstructed and also in use and that can be applied to springconstructions during the course of erection, and that is at once simple,substantial, practicable, efficient, durable and inexpensive. Theinvention consists of the construction and features, an embodiment ofwhich is illustrated in the accompanying drawing and described andclaimed hereinafter.

Figure 1 is a perspective of the invention shown as applied to asemi-elliptic leaf spring.

Fig. 2 is a perspective, on a larger scale, of the invention as appliedto an arm of the spring, parts being broken away for clarity.

Fig. 3 is a side elevation of a portion of the elliptic spring arm andshowing in detail the saddle construction, parts being broken away forclearness.

As is well known vehicle bodies are commonly supported on various typesof springs,

a semielliptic spring 2, Fig. 1, in which the spring comprisesessentially aseries or lamination of leaves superposed one upon theother and having their edges vertically alined or registered, the springstructure being fastened to an axle 3, for instance, by any suitableclip or fastening means 4. One end of the spring is ordinarily connectedto the rear overhanging end 5 of the chassis and the other end of thespring is connected at a point further along the frame, but not hereshown.

When the vehicle is passing over an obstacle the load on the spring 3causes the same to flex downwardly in proportion to the load and inproportion to the form and size of the obstruction, and in some casesthe spring 2 is flexed downwardly beyond a safe degree and again whenthe recoil of the spring occurs the load is moved violently and rapidlyup- Specification of Letters Patent.

invention comprises a device that is Patented June 8, 1922. SerialNo.336,389.

wardly,v and both the recoil action and the overload downward action areserious obections and it is an object of this invention to remedy thesame.

To that end I have provided a device that is reactive both on theoverload downward flexure of the spring also on the recoil of thespring, and a preferred embodiment ofthe wholly mounted on one arm, forinstance, of the spring 2. a

To accomplish this my dual acting spring involves a clip 10 ofproportions adapted to straddle the arm of the spring 2 and, preferably,the inner surface of the legs 11 are made plane as at 12 so as toprevent relative sh fting transversely or edgewise of the re: coilspring member or organization ,which comprises, in this case, a mainleaf 13 of suitable width and length to pass beneath the upper part ofthe clip '10 and between the .egs 11 thereof. There may be utilizedabove the main recoil spring 13 a shorter auxiliary spring leaf 14: alsopassing beneath the head of theclip 10, and the ends 1314 are perforatedas at 15 to receive a stop or adjusting member in the form of a screw 16having a squared head 16' and a threaded lower portion or body 16". a

The spring leaves 13-14 are, preferably, superposed somewhat above theto of the arm of the spring 2 as on a saddle 11 passed between the legs11 of the clip 10 and which may have its opposite edges notched as at 18to receive the legs 11. Extending parallel to the clip 10, and at oneend of the saddle 17 there is provided a fulcrum or upwardly standinglug 19 on which the superposed springs of the recoil device are mounted,and these springs are adapted to rock or tilt on the lug or shoulder 19as determined by the adjustment of the perforated ends of the recoilsprings according to the adjustment of the screw 16 which has upper andlower clamp nuts 20 binding the interposed leaves.

To secure the dual reaction of the improved shock absorber the free orouter end of the leaf 13 is shown as provided with a shackle or loop 21extending downwardly and around the movable end of the spring arm '2,the shackle having a transversely extending bar 22 underneath of themain spring arm 2. Upon the downward action of the main spring 2 thisbar is designed to engage with the lower adjacent surface of the springarm and thus. react through the of these springs agency of the spring13} to limit the downward fiexure of the main spring 2. Conversely, uponthe upward or recoil action of the main spring 2 its upper surface isdesigned to move into contact with the abutment member 23 suitablyconnected to the lower surface and adjacent the end ofthe recoil springleaf 13 so that the-recoil action ofthe main spring 2 is counteractedbythe spring 13 and the vibration andshock of its movement is absorbed bysaid spring 13.

If desired, a supplementary and initially acting recoil spring may beintroduced 'bew tween the recoil spring leaf 13'and the upper spring ofthe arm 2, and such leaf is indicated at 24c as resting upon thefulcrum. or shoulder 19 and is also perforate at its end adjacent to thesaddle 17 so as to receive the adjusting screw 16 while the opposite endof the'initially acting spring 24 terminates somewhat short of the upperrecoil spring 13, as clearly shown in Fig. 2.

From the above it will be seen that when for any reason there is anabnormal overdownward fiexure of the main spring arm 2 this will becounteracted through an engagement therewith of the shackle bar 22 thatis connected to the outer and free end' of the recoil spring 13.Conversely, upon the recoil of the main spring 2 when the main spring 2reaches a predetermined upward curvature it will engage the abutment 23that is mounted on the recoil spring 13 and this will again be broughtinto play to absorb the recoil action of the main spring.

The effective position of the shock absorbing device including thespring leaves 13, 1 1 and 24 can be readily varied by tilting the sametoward or from the movable end of the main spring 2 about the fulcrum orsupport 19, which forms a part of the saddle 17, and this may beaccomplished by releasing the clip 10 by unturning its nuts 10 and thenturning the screw 16 so that it will elevate the adjacent ends of thespring leaves and thus force the other ends of the leaves to ward theouter end of the spring arm 2.

After the desired adjustment has been completed the nuts 10' on the legsare again tigthened up and this will cause the firm seating oi therecoil springs on the fulcrum 19 and the abutment of the point of thescrew 16 against the adjacent surface formed by an extension of thesaddle 17. v

To tilt the outer ends of the springs 1314 away from the main spring 2,it is necessary to so turn the screw 16 as to shorten the distancebetween the adjacent ends of the leaves and the saddle 17, and afterthis is done the slack or play of the clip 10 is taken up by advancingthe nuts 10 on the threaded legs. Manifestly, by varying the angle ofthe recoil springs 13-14: the degree of compression and resistance ofthe initially acting spring 24 is also varied, this spring being curveddownwardly from the fulcrum 19 so as to be normally in contact with thetopmost leaf of the main spring 2.

If desired, the contact face of the abutment 23 may be provided with anoise reducing surface or pad 23', and for the purpose of preventing theattachment from bodily shifting along the spring arm 2 the lower surfaceof the saddle 17 may be corrugated as at 1.7 so as to bite into theupper surface of the spring, the latter being roughened as at 2' to aidin the holding of-the parts against shifting. In a 'similar manner theupper surface of: the transverse bar forming the bottom of the clip 10may be roughened as at 1 0. I

Obviously the bow of the clip 10 can be placed over the recoil springdevice in a plane vertically through the fulcrum 19 on which the recoilsprings may be rocked so that the loosening up of the fastening nuts 10can be eliminaed.

The front or end shackle 21 serves an important object in preventing theunit. when it .is applied to the spring arm 23, from swinging laterallyor edgewise as to the spring arm and lateral or edgewise movement of theinitial acting spring 2i will be prevented by reason of its connectionwith the pin 16 which passes through the hole provided therefor in theend of the leaf 24.

Various changes may be made without departing from the spirit of myinvention as claimed.

1' claim:

1. A shock absorber for wheeled vehicles having a spring arm, comprisinga saddle adapted to be mounted upon the arm, a spring mounted upon thesaddle and extended therefrom to overlap the spring arm and adapted toreact against the arm when the latter flexes beyond a given degree, andan intermediate spring member disposed between the arm and the springand acting initially only upon said arm in the recoil of the arm.

2. A shock absorber including a spring arm, an initially acting springfulcrumed thereon. a recoil spring upon said initially acting spring.clamping means cooperating with said spring arm and said springs, meansfor positioning the free end of said initially acting spring againstsaid spring arm and the free end of said recoil spring in spacedrelation from said spring arm, and a shackle cooperating with the springarm and the free end of said recoil spring.

in testimony whereof I have signed my name to this specification.

' ALEXANDER R. AFMNUT.

